A conventional shadow-mask CRT uses three electron beams deflected by a deflection coil. The beams traverse a perforated metal mask (shadow-mask) before impinging on a selected phosphor screen material. The selected phosphor formed on the inner surface of the screen comprises of a pattern of red, green and blue phosphors and a black matrix ("BM") which is formed between the phosphors. The three electron beams which pass through the shadow-mask converge on the screen and each beam impinges on one of the red, green and blue phosphors.
Generally, a process for forming a phosphor screen comprises first coating a photoresist on the inner surface of a panel. The photoresist is dried by heat or other means and exposed to UV rays irradiated through mask slots. The exposed panel is washed and developed to remove the unexposed photoresist and then dried.
A black matrix material is coated on the panel on which the photoresist-coated portion is regularly patterned. Thereafter, the panel is etched to produce the BM layer. Red, green and blue phosphors are sequentially coated on portions on which BM dots do not exist to produce a phosphor screen. As shown in FIG. 1, red, green, and blue phosphors individually exist in a conventional CRT. Various chemical elements having various decay time characteristics are conventionally used as red, green and blue phosphors. In particular, ZnS:Ag,CI and ZnS:Ag,AI phosphors are used as blue phosphor, and it takes 100-200 .mu.s for the blue phosphor to be decayed to have 10% luminescence compared to its full luminescence (10% decay time). Generally, in a CRT, the scanning speed of an electron beam scanning line to scan the blue phosphor is about 16 ms. As shown above, the decay time for a conventional blue phosphor is very short compared to the scanning speed of an electron beam scanning line in a conventional CRT, and as a result a flickering phenomena occurs. Due to the flickering phenomenon, a person who watches TV or a monitor may feel eye fatigue.